1. Field of the Invention
The design of large rotary machinery necessarily includes the provision of one or more journal bearings in order to support various rotating components of the machine and one or more thrust bearings to absorb the axial thrust loads which are imposed thereon. Such bearings must be supplied with suitable quantities of lubricating oil under pressure in order to establish a hydrodynamic film between the bearing surface and the rotating element.
In the event that loads in excess of that for which a particular bearing is designed are encountered, or upon a lack of sufficient lubricating oil at a bearing surface, high temperatures may be generated due to frictional forces which, if allowed to continue, would result in bearing failure and consequent serious damage to the machine.
Further, it is possible that, through ordinary wear, a bearing surface may become worn to such an extent as to represent a hazard to further operation of the machine.
Should either of the above-enumerated conditions exist in a machine during its operation, it would be desirable to shut the machine down and remedy the malfunction before the bearing fails completely, possibly resulting in serious and expensive damage to other parts of the machine. It is this problem to which the present invention is addressed, providing a probe which is disposed within a bearing at a location where it senses both bearing temperature and physical contact with a portion of the bearing in the event of excess wear or failure.
2. Description of the Prior Art
The prior art has recognized the problem of excess bearing temperature and includes various schemes for sensing same. For example, U.S. Pat. Nos. 2,961,875, and 3,052,123 show electrical temperature sensing elements disposed within a bearing at a location where they are responsive to excess bearing temperature. It should be noted, however, that none of these patents include the further capability to sense bearing wear or failure. Moreover, applicants are not aware of any prior art bearing probe which includes these combined features.
Although applicants are aware of prior art in which a probe is provided to sense bearing failure (see U.S. Pat. Nos. 3,508,241 and 3,897,116), these are comparatively complicated devices and, more importantly, do not include means for sensing bearing temperature as well.